Weight loss can be a challenging undertaking (even maintaining your weight can be tough when the holidays roll around). Make the most of your efforts with help from one of these five weight-management tools most valued by Lifehacker readers.

There's no magic bullet for fitness and weight loss—although most would argue "eat less, move more" is a excellent starting point. One pattern that is definitely prominent among the comments of Lifehacker readers in our call for contenders for this week's Hive Five, however, is that if there is a magic bullet for weight loss, it's tracking. Whether you're using a spreadsheet, a notebook, or some of the great web and mobile phone-based solutions you'll see below, the biggest element in our readers' weight-loss success has been tracking their food intake and exercise activity.

SparkPeople is a comprehensive weight-loss web site. A free membership gives you access to a variety of nutritional information and calorie-tracking tools, weight-tracking tools, and the enormous SparkPeople community. Personal pages, like mini-blogs within the SparkPeople site, help you publish your progress and connect with other users who have similar goals. You'll find no shortage of ways to track and analyze everything from the types of food you eat to the amount of weight you lift—and lose!—in the reports section of the site. SparkPeople is available in a scaled-down mobile version for use on your web-enabled phone or as an iPhone/iPod touch application.

Readers loved this tiny and free iPhone application. It sports an easy to use interface, a large database of foods and calorie values, and it has the ability to track your exercise times. Lose It! then combines that information—the food you've eaten and the exercise you've completed—and creates a chart you can access at any time during the day that tells you how many calories you've got left in the day and how close you are to your maximum. It won't scold you if your last 500 calories for the day is in a big piece of chocolate cake right before bed, but it's simple to use, and since most people keep their iPhone or iPod touch nearby all day, it's always with you.

NutriMirror isn't on the bleeding edge with multiple mobile applications, but it does offer a solid system for tracking your food intake, exercise patterns, weight, and other body measurements—dumping it all into useful reports. NutriMirror will tell you if you're meeting target goals for daily carbohydrate, fat, and protein intake, though you can adjust these settings if you're on a diet plan that has specific requirements. If you need to track your food intake when you're away from your computer, the site has an archive of of printable logs you can keep tucked in your wallet or purse.

LiveStrong is the health and wellness branch of Lance Armstrong's LiveStrong charity. The site is well designed and user friendly, and it has a heavy emphasis on overall health rather than simply tracking calories and weight. If all you want is a good tracking tool, The Daily Plate sub-section of the site will help with that, as will the iPhone app, which links into your LiveStrong account to help you track things away from home. You can also take advantage of LiveStrong "loops" for mapping out your local running, cycling, walking, and hiking routes. LiveStrong sports a large community with many subgroups catering to different needs and goals.

FitDay has one of the more spartan interfaces among the web-based selections in today's Hive, but that isn't necessarily a bad thing. Using FitDay you can track common stats like weight and calorie consumption, but you can also track interesting tangential metrics, like your level of hunger, level of energy, happiness, and so on. When generating reports, you can compare this data, which may provide interesting insights into changes you make in your diet and habits. FitDay is available as a webapp and a Windows application, also free. If you want to be able to sync your web-based account with the FitDay application however, you'll need a premium account, which runs $64 a year.

Now that you've had a chance to look over the top contenders for best weight-loss tool, it's time to log a vote for your favorite:

This week we've got an honorary mention, the Nintendo Wii Fit. It's not a cheap solution with the Wii + Wii Fit costing around $300, but many readers said that the fun factor combined with the tracking element of the Wii Fit software was enough to get them thinking about fitness and making more conscious dietary and exercise choices.

Didn't see your favorite featured? Can't believe anyone uses anything more than pen and paper? Let's hear from about it in the comments.